Effect of Solidification Coupling and Submerged Entry Nozzle Port Design on Slag Entrainment in a Slab Continuous‐Casting Mold

A three‐dimensional multiphysics model coupling large eddy simulation (LES), volume of fluid (VOF) multiphase flow, and solidification was developed to investigate slag entrainment in a slab continuous‐casting mold. The mold‐wall heat flux was prescribed using user‐defined functions (UDFs), and the model was validated against in‐plant meniscus velocities measured by the nail‐board method. Based on the captured steel–slag–gas interfacial evolution, three dominant entrainment mechanisms were identified, including shear‐induced interfacial instability, von Kármán vortex‐induced suction, and meniscus fluctuation‐driven entrainment. Compared with simulations without solidification, the formation of the solidified shell significantly attenuates the postimpingement upward backflow, reducing the peak time‐averaged meniscus velocity from 0.20 to 0.15–0.16 m/s, indicating that neglecting solidification can overestimate near‐meniscus kinetic energy and bias slag‐entrainment risk assessment. Furthermore, the effect of submerged entry nozzle (SEN) port design was evaluated by comparing two‐port and three‐port nozzles, showing that the three‐port nozzle disperses jet momentum and stabilizes meniscus fluctuations, decreasing the minimum variance of level fluctuations to 0.21 mm 2 and reducing the net slag entrainment rate from 0.00504 to 0.00447 kg/s.